Coil component

The present disclosure relates to a coil component and, more particularly, to a coil component having a structure in which a plurality of interlayer insulating films and a plurality of conductor layers are alternately stacked.

JP 2020-088330A discloses a coil component having a structure in which a plurality of interlayer insulating films and a plurality of conductor layers are alternately stacked. In the coil component described in JP 2020-088330A, two terminal electrodes are arranged in the stacking direction of the plurality of conductor layers, one of which is connected to one end of a coil pattern positioned in the lowermost layer, and the other one of which is connected to one end of a coil pattern positioned in the uppermost layer.

In the coil component described in JP 2020-088330A, the coil pattern has a substantially constant width.

It is therefore an object of the present disclosure to reduce a DC resistance by locally enlarging the width of a coil pattern.

A coil component according to the present disclosure includes: a coil part in which a plurality of interlayer insulating films and a plurality of conductor layers are alternately stacked; first and second terminal electrodes; and a magnetic element body in which the coil part and first and second terminal electrodes are embedded. The plurality of conductor layers include a first conductor layer positioned in the lowermost layer and a second conductor layer positioned in the uppermost layer. The first conductor layer includes a first coil pattern and a first terminal pattern provided independently of the first coil pattern and exposed from a first side surface of the magnetic element body. The second conductor layer includes a second coil pattern and a second terminal pattern provided independently of the second coil pattern and exposed from a second side surface of the magnetic element body that is positioned on the side opposite to the first side surface. The first terminal electrode is connected to one end of the first coil pattern through the second terminal pattern, and the second terminal electrode is connected to one end of the second coil pattern. The first terminal pattern includes a first linear part having a substantially constant pattern width in a first direction perpendicular to the first side surface of the magnetic element body, a first widened part positioned at one end side in a second direction along the first side surface of the magnetic element body and having a pattern width in the first direction larger than that of the first linear part, and a second widened part positioned at the other end side in the second direction and having a larger pattern width in the first direction than that of the first linear part. The outermost turn of the first coil pattern includes a first section provided along the first linear part of the first terminal pattern, a second section provided along the first widened part of the first terminal pattern, a third section provided along the second widened part of the first terminal pattern, a fourth section provided along the magnetic element body and positioned on the side opposite to the first section with respect to the second section, and a fifth section provided along the magnetic element body and positioned on the side opposite to the first section with respect to the third section. The pattern width of the first coil pattern is larger in the second and third sections than in the first, fourth, and fifth sections.

Preferred embodiments of the present disclosure will be explained below in detail with reference to the accompanying drawings.

is a schematic perspective view illustrating the outer appearance of a coil componentaccording to an embodiment of the present disclosure.is a schematic cross-sectional view of the coil component.

As illustrated in, the coil componentaccording to the present embodiment includes a magnetic element body, a coil part, and bump terminal electrodes Band B. The coil partand bump terminal electrodes Band Bare embedded in the magnetic element body. The magnetic element bodyis positioned in the inner diameter area and outside area of the coil partso as to sandwich the coil partin the z-direction (coil axis direction). The magnetic element bodyis a composite magnetic member containing magnetic metal filler made of iron (Fe) or a permalloy-based material and a resin binder and forms a magnetic path for magnetic flux generated by making a current flow in the coil part. The magnetic element bodyhas an upper surfaceconstituting the xy plane which is perpendicular to the z-direction (coil axis direction) and a pair of side surfacesandconstituting the yz plane which is perpendicular to the upper surface. The side surfacesandare positioned on the opposite sides. The surface of the terminal electrode Bis exposed from the upper surfaceand side surfaceof the magnetic element body. The surface of the terminal electrode Bis exposed from the upper surfaceand side surfaceof the magnetic element body. Upon mounting of the coil component, the terminal electrodes Band Bare soldered onto a circuit board such that the upper surfaceof the magnetic element bodyfaces the circuit board.

The coil partincludes interlayer insulating filmstoand conductor layers Lto Lwhich are alternately stacked in the coil axis direction. The conductor layers Lto Lhave coils patterns,,, and, respectively.

are plan views illustrating the pattern shapes of the conductor layers Lto L, respectively.

As illustrated in, the conductor layer Lis formed on the surface of the interlayer insulating filmand includes the coil patternand a terminal pattern. An outer peripheral endof the coil patternhas an enlarged area and overlaps the terminal electrode Bas viewed in the z-direction. The terminal patternis separated from the coil patternwithin the surface and overlaps the terminal electrode Bas viewed in the z-direction. The terminal patternincludes a linear part, a widened part, and a widened part. The linear parthas a substantially constant pattern width in the x-direction. The widened partsandare positioned respectively at one end side and the other end side in the y-direction and each have a pattern width in the x-direction larger than that of the linear part. The widened partsandhave a shape in which the pattern width thereof in the x-direction increases toward the end portion in the y-direction. Accordingly, the edge of each of the widened partsandthat is positioned on the side opposite to the side surfaceof the magnetic element bodyextends obliquely with respect to the y-direction. On the other hand, the edge of the linear partthat is positioned on the side opposite to the side surfaceof the magnetic element bodyextends substantially linearly in the y-direction.

The outermost turn of the coil patternincludes a section Sextending in substantially the y-direction along the linear partof the terminal pattern, a section Sprovided along the widened partof the terminal pattern, a section Sprovided along the widened partof the terminal pattern, a section Sprovided along the magnetic element bodyand positioned on the side opposite to the section Swith respect to the section S, and a section Sprovided along the magnetic element bodyand positioned on the side opposite to the section Swith respect to the section S. The section Sis positioned closer to the outer peripheral endthan the section Sand includes a part extending in the x-direction. The section Sis positioned closer to an inner peripheral endthan the section Sand includes a part extending in the x-direction. The thus configured conductor layer Lis covered with the interlayer insulating film.

As illustrated in, the pattern width of the coil patternin the radial direction is not constant, but pattern widths Wand Wof the respective sections Sand Sare larger than pattern widths W, W, and Wof the respective sections S, S, and S. That is, the outermost turn of the coil patternradially protrudes outward between the sections Sand Sand between the sections Sand S.

The outer peripheral edges of the respective sections Sto Sof the coil patternextend along the terminal patternthrough the interlayer insulating film. Thus, the outer peripheral edge of the section Sextends substantially linearly in the y-direction with the result that the pattern width Wof the section Sincreases toward the sections Sand Sfrom the center in the y-direction. The outer peripheral edges of the respective sections Sand Seach have a part extending in the x-direction. Thus, an increase in the pattern width per unit peripheral length from the section Stoward the section Sand an increase in the pattern width per unit peripheral length from the section Stoward the section Sare larger than an increase in the pattern width per unit peripheral length from the section Stoward the sections Sand S.

As illustrated in, the conductor layer Lis formed on the surface of the interlayer insulating filmand includes the coil patternand the terminal patternsand. The terminal patternsandare separated from the coil patternwithin the surface and overlap respectively the terminal electrodes Band Bas viewed in the z-direction. The terminal patternis connected to the outer peripheral endof the coil patternthrough a via conductorpenetrating the interlayer insulating film. An inner peripheral endof the coil patternis connected to the inner peripheral endof the coil patternthrough a via conductorpenetrating the interlayer insulating film.

The terminal patternhas the same shape as the terminal patternincluded in the conductor layer L. That is, the terminal patternincludes a linear parthaving a substantially constant pattern width in the x-direction and widened partsandpositioned respectively at one end side and the other end side in the y-direction and each have a pattern width in the x-direction larger than that of the linear part. The widened partsandhave a shape in which the pattern width thereof in the x-direction increases toward the end portion in the y-direction. Accordingly, the edge of each of the widened partsandthat is positioned on the side opposite to the side surfaceof the magnetic element bodyextends obliquely with respect to the y-direction. On the other hand, the edge of the linear partthat is positioned on the side opposite to the side surfaceof the magnetic element bodyextends substantially linearly in the y-direction.

The terminal patternincludes a nonlinear partwhose pattern width in the x-direction increases with distance from the center portion in the y-direction and a linear partpositioned at one end side in the y-direction and having a substantially constant pattern width in the x-direction. The edge of the nonlinear partpositioned on the side opposite to the side surfaceof the magnetic element bodyhas a circular-arc shape. On the other hand, the edge of the linear partpositioned on the side opposite to the side surfaceof the magnetic element bodyextends substantially linearly in the y-direction.

The outermost turn of the coil patternincludes a section Sextending in substantially the y-direction along the linear partof the terminal pattern, a section Sprovided along the widened partof the terminal pattern, a section Sprovided along the widened partof the terminal pattern, a section Sprovided along the magnetic element bodyand positioned on the side opposite to the section Swith respect to the section S, a section Sprovided along the magnetic element bodyand positioned on the side opposite to the section Swith respect to the section S, a sectionprovided along the nonlinear partof the terminal pattern, and a section Sprovided along the linear partof the terminal pattern. The section Sis positioned between the section Sand the section Sand includes a part extending in the x-direction. The section Sis positioned closer to an outer peripheral endthan the section Sand includes a part extending in the x-direction. The thus configured conductor layer Lis covered with the interlayer insulating film.

As illustrated in, the pattern width of the coil patternin the radial direction is not constant, but pattern widths Wand Wof the respective sections Sand Sare larger than pattern widths W, W, and Wof the respective sections S, S, and S, and a pattern width Wof the section Sis larger than the pattern widths Wand Wof the respective sections Sand S. That is, the outermost turn of the coil pattern radially protrudes outward between the sections Sand Sand between the sections Sand S.

The outer peripheral edges of the respective sections Sto Sof the coil patternextend along the terminal patternthrough the interlayer insulating film. Thus, the outer peripheral edge of the section Sextends substantially linearly in the y-direction with the result that the pattern width Wof the section Sincreases toward the sections Sand Sfrom the center in the y-direction. The outer peripheral edges of the respective sections Sand Seach have a part extending in the x-direction. Thus, an increase in the pattern width per unit peripheral length from the section Stoward the section Sand an increase in the pattern width per unit peripheral length from the section Stoward the section Sare larger than an increase in the pattern width per unit peripheral length from the section Stoward the sections Sand S. Similarly, the outer peripheral edge of the sectionhas a part extending in the x-direction. Thus, an increase in the pattern width per unit peripheral length from the section Stoward the section Sis larger than an increase in the pattern width per unit peripheral length from the section Stoward the section S.

As illustrated in, the conductor layer Lis formed on the surface of the interlayer insulating filmand includes the coil patternand terminal patternsand. The terminal patternsandare separated from the coil patternwithin the surface and overlap respectively the terminal electrodes Band Bas viewed in the z-direction. The terminal patternis connected to the terminal patternof the conductor layer Lthrough a via conductorpenetrating the interlayer insulating film. The planar position of the via conductordiffers from the planar position of the via conductor, thereby preventing a recess of the conductor layer caused due to stacking of the via conductors. Further, an outer peripheral endof the coil patternis connected to the outer peripheral endof the coil patternthrough a via conductorpenetrating the interlayer insulating film.

The terminal patternhas the same shape as those of the terminal patternsandincluded respectively in the conductor layers Land L. That is, the terminal patternincludes a linear parthaving a substantially constant pattern width in the x-direction and widened partsandpositioned respectively at one end side and the other end side in the y-direction and each have a pattern width in the x-direction larger than that of the linear part. The widened partsandhave a shape in which the pattern width thereof in the x-direction increases toward the end portion in the y-direction. Accordingly, the edge of each of the widened partsandthat is positioned on the side opposite to the side surfaceof the magnetic element bodyextends obliquely with respect to the y-direction. On the other hand, the edge of the linear partthat is positioned on the side opposite to the side surfaceof the magnetic element bodyextends substantially linearly in the y-direction.

The terminal patternhas the same shape as the terminal patternincluded in the conductor layer L. That is, the terminal patternincludes a nonlinear partwhose pattern width in the x-direction increases with distance from the center portion in the y-direction and a linear partpositioned at one end side in the y-direction and having a substantially constant pattern width in the x-direction. The edge of the nonlinear partpositioned on the side opposite to the side surfaceof the magnetic element bodyhas a circular-arc shape. On the other hand, the edge of the linear partpositioned on the side opposite to the side surfaceof the magnetic element bodyextends substantially linearly in the y-direction.

The outermost turn of the coil patternincludes a section Sextending in substantially the y-direction along the linear partof the terminal pattern, a section Sprovided along the widened partof the terminal pattern, a section Sprovided along the widened partof the terminal pattern, a section Sprovided along the magnetic element bodyand positioned on the side opposite to the section Swith respect to the section S, a section Sprovided along the magnetic element bodyand positioned on the side opposite to the section Swith respect to the section S, a section Sprovided along the nonlinear partof the terminal pattern, and a section Sprovided along the linear partof the terminal pattern. The section Sis positioned between the section Sand the section Sand includes a part extending in the x-direction. The section Sis positioned closer to an inner peripheral endthan the section Sand includes a part extending in the x-direction. The thus configured conductor layer Lis covered with the interlayer insulating film.

As illustrated in, the pattern width of the coil patternin the radial direction is not constant, but pattern widths Wand Wof the respective sections Sand Sare larger than pattern widths W, W, and Wof the respective sections S, S, and S, and a pattern width Wof the section Sis larger than the pattern widths Wand Wof the respective sections Sand S. That is, the outermost turn of the coil patternradially protrudes outward between the sections Sand S, between the sections Sand Sand between the sections Sand S.

The outer peripheral edges of the respective sections Sto Sof the coil patternextend along the terminal patternthrough the interlayer insulating film. Thus, the outer peripheral edge of the section Sextends substantially linearly in the y-direction with the result that the pattern width Wof the section Sincreases toward the sections Sand Sfrom the center in the y-direction. The outer peripheral edges of the respective sections Sand Seach have a part extending in the x-direction. Thus, an increase in the pattern width per unit peripheral length from the section Stoward the section Sand an increase in the pattern width per unit peripheral length from the section Stoward the section Sare larger than an increase in the pattern width per unit peripheral length from the section Stoward the sections Sand S. Similarly, the outer peripheral edge of the section Shas a part extending in the x-direction. Thus, an increase in the pattern width per unit peripheral length from the section Stoward the section Sis larger than an increase in the pattern width per unit peripheral length from the section Stoward the section S.

As illustrated in, the conductor layer Lis formed on the surface of the interlayer insulating filmand includes the coil patternand a terminal pattern. The terminal patternis separated from the coil patternwithin the surface and overlaps the terminal electrode Bas viewed in the z-direction. The terminal patternis connected to the terminal patternthrough a via conductorpenetrating the interlayer insulating film. The planar position of the via conductordiffers from the planar position of the via conductor, thereby preventing a recess of the conductor layer caused due to stacking of the via conductors. Further, an inner peripheral endof the coil patternis connected to the inner peripheral endof the coil patternthrough a via conductorpenetrating the interlayer insulating film.

The terminal patternhas the same shape as the terminal patternsandincluded respectively in the conductor layers Land L. That is, the terminal patternincludes a nonlinear partwhose pattern width in the x-direction increases with distance from the center portion in the y-direction and a linear partpositioned at one end side in the y-direction and having a substantially constant pattern width in the x-direction. The edge of the nonlinear partpositioned on the side opposite to the side surfaceof the magnetic element bodyhas a circular-arc shape. On the other hand, the edge of the linear partpositioned on the side opposite to the side surfaceof the magnetic element bodyextends substantially linearly in the y-direction.

The outermost turn of the coil patternincludes a section Sprovided along the nonlinear partof the terminal pattern, a section Sprovided along the linear partof the terminal pattern, and a section Spositioned on the side opposite to the section Swith respect to the section S. The section Sis positioned between the section Sand an outer peripheral endand includes a part extending in the x-direction. The thus configured conductor layer Lis covered with the interlayer insulating film.

As illustrated in, the pattern width of the coil patternin the radial direction is not constant, and a pattern width Wof the sectionis larger than pattern widths Wand Wof the respective sections Sand S. That is, the outermost turn of the coil pattern radially protrudes outward between the sections Sand S. The outer peripheral edge of the section Sincludes a part extending in the x-direction. Thus, an increase in the pattern width per unit peripheral length from the section Stoward the section Sis larger than an increase in the pattern width per unit peripheral length from the section Stoward the section S.

The bump terminal electrodes Band Bare provided on the interlayer insulating film. The terminal electrode Bis connected to the terminal patternthrough a via conductorpenetrating the interlayer insulating film. The terminal electrode Bis connected to the outer peripheral endof the coil patternthrough a via conductorpenetrating the interlayer insulating film. The planar position of the via conductordiffers from the planer position of the via conductor, thereby preventing a recess of the conductor layer caused due to stacking of the via conductors. Further, the via conductoris provided so as to partly overlap the section Sof the coil patternfor ensuring a margin upon singulation of the coil componentby dicing.

With the above configuration, the terminal electrode Bis connected to the outer peripheral endof the coil patternthrough the terminal patterns,, and. The outer peripheral endof the coil patternand the terminal patterns,, andare exposed from the side surfaceof the magnetic element body. On the other hand, the terminal electrode Bis connected to the outer peripheral endof the coil pattern. The terminal patterns,, andand the outer peripheral endof the coil patternare exposed from the side surfaceof the magnetic element body.

The pattern width of each of the coil patterns,,, andis not constant but enlarged in the vicinity of the y-direction end portion of the terminal pattern to which each of the coil patterns,,, andcorresponds, thus allowing reduction of a DC resistance. In addition, the terminal patterns,, andrespectively have the linear parts,, and, and the outer peripheral edges of the coil patterns,, andadjacent respectively to the linear parts,, andare substantially linear, so that, as compared to when the inner peripheral edges of the terminal patterns,, andhave a circular-arc shape, it is possible to ensure a sufficient pattern width for the coil patterns,, and. The reason why the inner peripheral edge of each of the linear parts,, andis made linear is to reduce the area of each of the terminal patterns,, andas much as possible while ensuring a minimum required margin in the x-direction which takes into consideration misalignment upon singulation of the coil componentby dicing. This can enlarge the pattern width of each of the coil patterns,, andby a reduction in the area of each of the terminal patterns,, and. This can be achieved because the terminal patterns,, andare not connected but insulated from one another to eliminate the need of providing via conductors therefor, thus facilitating a reduction in the x-direction width.

Further, the widened partsandprovided at both ends of the linear partin the y-direction, widened partsandprovided at both ends of the linear partin the y-direction, and widened partsandprovided at both ends of the linear partin the y-direction play a role of improving the manufacturing yield of the coil componentaccording to the present embodiment. That is, by providing such widened parts, nonlinear parts corresponding to the widened parts are included in resist patterns positioned between the coil patterns,, andand terminal patterns,, andupon formation of the conductor layers L, L, and Lby electrolytic plating, so that flow of a plating solution used for electrolytic plating is suppressed by the nonlinear parts of the resist patterns, with the result that collapse of the resist patterns is less likely to occur.

On the other hand, the via conductors,,, andare connected with any of the terminal patterns,, and, so that, considering the formation margin of the via conductors,,, and, it is necessary to ensure a larger width in the x-direction for the terminal patterns,, andthan for the terminal patterns,, and. For this reason, in place of providing the linear parts,, andfor the terminal patterns,, and, the inner peripheral edge of each of the terminal patterns,, andis formed into a circular-arc shape. Even in this case, at the y-direction end portions of the terminal patterns,, andwhere the via conductors,,, andare not formed, the linear parts,, andare formed to reduce the width in the x-direction, and correspondingly, the pattern width of each of the coil patterns,, andis enlarged to thereby reduce a DC resistance.

When the above-described pattern widths Wto W, Wto W, Wto W, and W, W, Wvary in the peripheral direction, the pattern width may be defined by the average width.

While the preferred embodiment of the present disclosure has been described, the present disclosure is not limited to the above embodiment, and various modifications may be made within the scope of the present disclosure, and all such modifications are included in the present disclosure.

For example, although the four conductor layers Lto Lare stacked through the interlayer insulating films in the above embodiment, the number of conductor layers to be stacked is not limited to this, and a three-layer structure or a five-or-more-layer structure may be adopted.

The technology according to the present disclosure includes the following configuration examples but not limited thereto.

A coil component according to the present disclosure includes: a coil part in which a plurality of interlayer insulating films and a plurality of conductor layers are alternately stacked; first and second terminal electrodes; and a magnetic element body in which the coil part and first and second terminal electrodes are embedded. The plurality of conductor layers include a first conductor layer positioned in the lowermost layer and a second conductor layer positioned in the uppermost layer. The first conductor layer includes a first coil pattern and a first terminal pattern provided independently of the first coil pattern and exposed from a first side surface of the magnetic element body. The second conductor layer includes a second coil pattern and a second terminal pattern provided independently of the second coil pattern and exposed from a second side surface of the magnetic element body that is positioned on the side opposite to the first side surface. The first terminal electrode is connected to one end of the first coil pattern through the second terminal pattern, and the second terminal electrode is connected to one end of the second coil pattern. The first terminal pattern includes a first linear part having a substantially constant pattern width in a first direction perpendicular to the first side surface of the magnetic element body, a first widened part positioned at one end side in a second direction along the first side surface of the magnetic element body and having a pattern width in the first direction larger than that of the first linear part, and a second widened part positioned at the other end side in the second direction and having a larger pattern width in the first direction than that of the first linear part. The outermost turn of the first coil pattern includes a first section provided along the first linear part of the first terminal pattern, a second section provided along the first widened part of the first terminal pattern, a third section provided along the second widened part of the first terminal pattern, a fourth section provided along the magnetic element body and positioned on the side opposite to the first section with respect to the second section, and a fifth section provided along the magnetic element body and positioned on the side opposite to the first section with respect to the third section. The pattern width of the first coil pattern is larger in the second and third sections than in the first, fourth, and fifth sections.

According to the present disclosure, the pattern width of the first coil pattern is locally enlarged, thereby allowing a reduction in DC resistance.

In the present disclosure, the first widened part of the first terminal pattern may have a shape in which the pattern width thereof in the first direction increases toward the one end in the second direction, and the second widened part of the first terminal pattern may have a shape in which the pattern width thereof in the first direction increases toward the other end in the second direction. This makes it possible to further enlarge the pattern width of the first coil pattern in the third and fourth sections.

In the present disclosure, the pattern width of the first coil pattern in the first section may increase toward the second and third sections from the center in the second direction. This makes it possible to further enlarge the pattern width of the first coil pattern in the first section.

In the present disclosure, the second and third sections of the first coil pattern may each have an outer peripheral edge extending in the first direction. This makes it possible to further enlarge the pattern width of the first coil pattern in the second and third sections.

In the present disclosure, the second terminal pattern may include a nonlinear part whose pattern width in the first direction increases with distance from the center portion in the second direction and a second linear part positioned at one end side in the second direction and having a substantially constant pattern width in the first direction. The outermost turn of the second coil pattern may include a sixth section provided along the nonlinear part of the second terminal pattern, a seventh section provided along the second linear part of the second terminal pattern, and an eighth section provided along the magnetic element body and positioned closer to the one end of the second coil pattern than the seventh section. The pattern width of the second coil pattern may be larger in the seventh section than in the sixth and eighth sections. Thus, the pattern width of the second coil pattern is locally enlarged, allowing a further reduction in DC resistance.

In the present disclosure, the plurality of conductor layers may further include a third conductor layer positioned between the first and second conductor layers. The third conductor layer may include a third coil pattern, a third terminal pattern exposed from the first side surface of the magnetic element body, and a fourth terminal pattern exposed from the second side surface of the magnetic element body. The first terminal electrode may be connected to the one end of the first coil pattern through the second and fourth terminal patterns. The third terminal pattern may include a third linear part having a substantially constant pattern width in the first direction, a third widened part positioned at one end side in the second direction and having a larger pattern width in the first direction than that of the third linear part, and a fourth widened part positioned at the other end side in the second direction and having a larger pattern width in the first direction than that of the third linear part. The outermost turn of the third coil pattern may include a ninth section provided along the third linear part of the third terminal pattern, a tenth section provided along the third widened part of the third terminal pattern, an eleventh section provided along the fourth widened part of the third terminal pattern, a twelfth section provided along the magnetic element body and positioned on the side opposite to the ninth section with respect to the tenth section, and a thirteenth section provided along the magnetic element body and positioned on the side opposite to the ninth section with respect to the eleventh section. The pattern width of the third coil pattern is larger in the tenth and eleventh sections than in the ninth, twelfth, and thirteenth sections. Thus, the pattern width of the third coil pattern is locally enlarged, allowing a further reduction in DC resistance.

As described above, according to the present disclosure, the pattern width of the coil pattern is locally enlarged, thus allowing a reduction in DC resistance.